Walsh's bipolar disorder is characterized by episodes of mania and depression. During manic episodes, he may experience increased energy, racing thoughts, and impulsive behavior. During depressive episodes, he may experience feelings of sadness, hopelessness, and worthlessness.
Walsh has also struggled with alcoholism and drug addiction. He has said that he first started drinking alcohol when he was 12 years old and that he began using drugs in his late teens.
Walsh has been sober since 1993. He has said that he credits his recovery to a combination of therapy, medication, and support from his family and friends.